Degree of modulation-

Options

A. can take any value
B. should be less than `100%`
C. should excess `100%`
D. none of these

Answer

To solve the problem of determining the degree of modulation, we will follow these steps:

### Step-by-Step Solution:

1. **Understanding the Degree of Modulation**:
The degree of modulation (also known as modulation index, denoted as \( \mu \)) is defined as the ratio of the amplitude of the message signal (\( A_m \)) to the amplitude of the carrier signal (\( A_c \)). Mathematically, it is expressed as:
\[ \mu = \frac{A_m}{A_c} \]

2. **Identifying the Conditions**:
The degree of modulation can take values from 0 to 1 (or 0% to 100%). If \( A_m \) is greater than \( A_c \), then \( \mu \) will exceed 1, which corresponds to over-modulation. This situation is undesirable as it leads to distortion and loss of information in the transmitted signal.

3. **Analyzing the Modulation Index**:
- If \( \mu < 1 \) (or \( \mu < 100\% \)), the modulation is considered normal.
- If \( \mu = 1 \) (or \( \mu = 100\% \)), the modulation is at its maximum without distortion.
- If \( \mu > 1 \) (or \( \mu > 100\% \)), it is termed over-modulation, which can corrupt the transmitted signal.

4. **Conclusion**:
To ensure effective communication without distortion, the degree of modulation must be less than or equal to 100%. Therefore, the correct answer to the question regarding the degree of modulation is that it should be less than 100%.

### Final Answer:
The degree of modulation should be less than 100%.